Add downloadPath to attachments after import to support resumable download

ts/test-electron/backup/filePointer_test.ts

@@ -40,7 +40,8 @@ describe('convertFilePointerToAttachment', () => {
           digest: Bytes.fromString('digest'),
           uploadTimestamp: Long.fromNumber(1970),
         }),
-      })
+      }),
+      { _createName: () => 'downloadPath' }
     );
 
     assert.deepStrictEqual(result, {
@@ -58,6 +59,7 @@ describe('convertFilePointerToAttachment', () => {
       uploadTimestamp: 1970,
       incrementalMac: Bytes.toBase64(Bytes.fromString('incrementalMac')),
       incrementalMacChunkSize: 1000,
+      downloadPath: 'downloadPath',
     });
   });
 
@@ -81,7 +83,8 @@ describe('convertFilePointerToAttachment', () => {
           transitCdnKey: 'transitCdnKey',
           transitCdnNumber: 2,
         }),
-      })
+      }),
+      { _createName: () => 'downloadPath' }
     );
 
     assert.deepStrictEqual(result, {
@@ -102,6 +105,7 @@ describe('convertFilePointerToAttachment', () => {
         mediaName: 'mediaName',
         cdnNumber: 3,
       },
+      downloadPath: 'downloadPath',
     });
   });
 
@@ -139,12 +143,14 @@ describe('convertFilePointerToAttachment', () => {
     const result = convertFilePointerToAttachment(
       new Backups.FilePointer({
         backupLocator: new Backups.FilePointer.BackupLocator(),
-      })
+      }),
+      { _createName: () => 'downloadPath' }
     );
 
     assert.deepStrictEqual(result, {
       contentType: APPLICATION_OCTET_STREAM,
       size: 0,
+      downloadPath: 'downloadPath',
       width: undefined,
       height: undefined,
       blurHash: undefined,